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Congenital renal disorders: Pathology review

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Questions

USMLE® Step 1 style questions USMLE

of complete

A 25-year-old female comes to the primary care physician for a follow-up appointment. The patient is currently asymptomatic and denies increased urinary frequency or dysuria. However, she has had multiple urinary tract infections during the past year, each of which resolved with antibiotic therapy. Additionally, the patient has had 3 episodes of calcium oxalate nephrolithiasis treated with conservative measures. She is sexually active, in a monogamous relationship, and uses condoms consistently. Temperature is 37.0°C (98.6°F), pulse is 65/min, and blood pressure is 120/80 mmHg. Physical examination shows no abnormalities. Urinalysis and IV pyelography are obtained and the results are shown below:  
 
 Urine  
 Color  Yellow 
 Clarity  Clear 
 Erythrocytes  8/hpf 
 Leukocytes  2/hpf 
 pH   5.5 
 Nitrates  Negative 
 Glucose   Negative 
 Protein  Negative 
 Bacteria   None 
 Sediment   None 


Image reproduced from Radiopedia  
Which of the following is the most likely underlying cause of this patient condition?  

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Content Reviewers

Yifan Xiao, MD,Filip Vasiljević, MD

Two people came to the Nephrology ward one day.

The first is 29 year old Dan, who presents with hypertension, gross hematuria, and flank pain.

Dan’s family history showed that his grandmother died of a berry aneurysm.

Next is 35 year old Heather.

She doesn’t present have any symptoms, but she has been referred to the nephrology clinic because her primary care doctor discovered that she her kidneys have a “weird shape” on an abdominal x-ray.

Both individuals underwent abdominal ultrasound.

Dan had many cysts of different sizes on both kidneys, while Heather’s kidneys are located lower than normal and appear fused together.

Both Dan and Heather have congenital renal disorders.

The renal system starts developing during week 4 of intrauterine life.

It comes from the mesoderm, which is one of the three primitive germinal layers.

More specifically, it develops from a portion of the mesoderm called the intermediate mesoderm.

The intermediate mesoderm on either side of the embryo condenses to form a cylindrical structure called the urogenital ridge, and a portion of the urogenital ridge called the nephrogenic cord gives rise to urinary structures.

During renal development, the nephrogenic cord gives rise to three sets of structures: the nonfunctional pronephros in the embryo’s head region which regresses by the end of week 4.

Then, the mesonephros forms, appears in the thoracic and upper lumbar region and acts as temporary kidneys until they regress in week 12.

Finally the metanephros develops in the pelvic region, and it forms the permanent kidneys.

Ok, the metanephros sprout small buds called the ureteric buds.

At the same time, the intermediate mesoderm gives rise to another tissue called the metanephric blastema.

The blastema release growth factors that stimulates the ureteric bud to become the ureter, the renal pelvis, the renal calyces, and the collecting ducts.

Meanwhile, the ureteric bud release growth factors that cause the metanephric blastema to develop into nephrons.

Sources

  1. "Robbins Basic Pathology" Elsevier (2017)
  2. "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
  3. "Practical Renal Pathology, A Diagnostic Approach E-Book" Elsevier Health Sciences (2012)
  4. "Campbell-Walsh Urology" Elsevier Health Sciences (2015)
  5. "Ultrasonography of the Kidney: A Pictorial Review" Diagnostics (2015)
  6. "Renal Cystic Diseases" Advances in Anatomic Pathology (2006)
  7. "Kallmann syndrome: phenotype and genotype of hypogonadotropic hypogonadism" Metabolism (2018)